1. Field of the Invention
The present invention relates to an analytical system, analytical method and a flow-path structure thereof capable of performing separation of a sample or a working fluid comprising different components with different characteristics by a uniform division process including centrifugal and capillary forces. The sample or the working fluid serves as a carrier for biochemical detection. Particularly, the present invention relates to an analytical system, analytical method and a flow-path structure thereof capable of performing separation of a sample or a working fluid comprising different components with different characteristics by using a uniform dividing compartment with varied geometrical shapes having gradually-increasing flow resistances, eliminating interference of a sample injection error using buffering compartments, separating substances or components with different specific gravities using a sinking chamber of a collecting compartment, adjusting excess working fluid using an overflowing compartment and metering the working fluid using a constant-quantity detection compartment, thereby increasing biochemical detection yield.
2. Description of the Related Art
In general, a conventional fluid separation device has a complicated structure. U.S. Pat. No. 6,548,788, for example, discloses methods and an apparatus for performing microanalytic and microsynthetic analyses and procedures. The fluid separation apparatus comprises a microchannel to control the movement of fluid. However, the microchannel must be manufactured by micromachining technology. Thus, when compared with plastic injection technology, the cost of the fluid separation apparatus is high.
U.S. Pat. Nos. 5,061,381 and 5,089,417 also disclose fluid separation devices having complicated structures and high manufacturing costs.
For separating blood cells, conventional blood detection methods are roughly classified into membrane-filtering methods and fluidic chip methods. The advantage of the membrane-filtering method is that it is simplistic. For example, U.S. Pat. No. 5,110,724 discloses an assay device utilizing membranes to separate blood cells and guide plasma into a reaction display region. However, due to biochemical reaction limitations, subsequent operations and tests on blood cells related to immune analysis cannot be performed. For the fluidic chip method, the process is complicated. The fluidic chip method comprises sample constant-quantity, dilution, mixing, centrifugal, distributing and detection processes. For example, U.S. Pat. No. 5,242,606 discloses a fluid separation device having a method comprising sample injection, diluted solution mixing, centrifugal, and distribution and constant-quantity detection processes. However, the process gets more complex and the number of required samples increases when the size of the chip increases. Moreover, the volume of the injected blood in comparison with the actual sampled blood changes due to blood remaining in the injector caused by viscosity. For example, the volume of the blood to be sampled by the injector may be 100 μL and the actual volume of the blood injected into the chip may be 98 μL. Thus, 2 μL of blood is left on the walls of the injector, injection regions and outside of the micro flow structure, thereby causing an insufficient volume of the blood to be injected into the microchannels. Additionally, actual volume of the injected fluid is influenced by human error when the injector is manually operated or by hands.